1. Field of the Invention
The present invention relates to an improved pad cup for a woodwind instrument, and more particularly relates to an improvement in an airtight closure formed by a pad cup and a sound hole in a wood-wind such as a clarinet or a saxophone.
Conventionally, a pad cup is held by a key rod which rotates axially when a key associated with the pad cup is manually operated. The cup has a cylindrical shape which is closed at one end and which accommodates a pad. The pad includes, from the closed end to the open end of the cup: a substrate made of high quality paper, a sheet made of felt, and a bag made of either animal skin or bladder covering the substrate and the sheet. The pad cup is mounted to the woodwind in an arrangement such that the pad faces the associated sound hole in the woodwind and that, when the associated key is manually operated, the pad closes the sound hole. This closure by the pad requires a high degree of airtightness in order to avoid any changes in tonal pitch, tone volume and tone color when the woodwind is played.
Bags made of animal skin are highly durable but have many pores. Such pores cause air leaks thereby preventing the sound hole from being closed with a high degree of airtightness. This causes an unstable performance of the woodwind and a poor rise of sounds. When a bladder bag is used, the pad can close the sound hole with a high degree of airtightness but the endurance of the bladder bag is poor compared to that of a skin bag. Thus, in the conventional art, endurance of a pad cup is not compatible with a highly airtight closure of sound holes.